On a Mercruiser 8.2L MIE inboard, I'm going to replace the impellers. They were replaced a couple of years ago, and I'm looking to replace them now before they fail.

So, here's the question. Replace just the impellers and o ring, or go ahead and get the entire plastic housing kit? The kit includes the 1 piece plastic body, impeller, o ring, wear plate, and new bolts/washers.

The current impellers haven't failed, I'm just doing a bit of preventative maint.

Diff in cost of the whole kit vs. the impeller and o ring kit is around $50 or $60.

What are the thoughts?

Thanks, Brad

June 23rd, 2011, 15:19

TimG

Brad this will totally be up to you, I have done both. How old is the sterndrive? You can pull it apart and if the plastic housing (water pump cover) and wear plate are in excellent shape then just replace the impeller and o-ring. Those covers do however overtime tend to become brittle and chalky, on my old Type I sterndrive the cover was chalky looking and would leave a white streak on your finger, to test it I tapped it with a screwdriver and it shattered. If that is the case then definitely replace them.

I am the type of person that would replace the whole assembly if the unit was old, just for the piece of mind. I think I noticed you have a Formula? If that is the case since you have a higher performance boat, replace them you don't want to run the risk of overheating an engine.

When you do the repair take lots of pictures and we can add them here as a how to....